Justin Timberlake became involved in an onstage spat with a fan after he saw the woman flipping her middle finger at him during a show in Pennsylvania.

Video footage from a concert in Philadelphia has emerged online and shows the star calling the fan out after spotting the rude gesture.

The singer told the female gig-goer, "Why are you flipping me off? You got second row to flip me the bird? That makes no f**king sense. You wanted me to see it? But you're in the second row, you didn't have to flip me off. I see you in the second row."

Timberlake goes on to give a comedy impersonation of the woman, flipping his own finger to the audience and encouraging them to all join in with the gesture, adding, "Let's all do it at the same time so we can get this over with... That's the weirdest moment I've ever had with a crowd. Thank you."